Physical and Chemical Changes

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Examples include melting, freezing, and dissolving.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. It involves a chemical reaction and includes processes like burning, rusting, and baking.

Front

What are some signs that a chemical reaction has occurred?

Back

Signs of a chemical reaction include the formation of a gas, color change, temperature change, formation of a precipitate, and emission of light.

Front

Is cutting a log into small pieces a chemical change?

Back

No, cutting a log into small pieces is a physical change because the chemical composition of the wood remains the same.

Front

Is melting butter for popcorn a chemical or physical change?

Back

Melting butter for popcorn is a physical change because it changes the state of the butter from solid to liquid without altering its chemical structure.

Front

What is an example of a chemical reaction?

Back

Baking cookies in an oven is an example of a chemical reaction because it involves a chemical change where new substances are formed.

Front

What does fizzing indicate in a reaction?

Back

Fizzing indicates a chemical change, often due to the release of gas during a reaction.

Front

What happens during a physical change?

Back

During a physical change, the form of a substance changes, but its chemical identity remains the same.

Front

Can a physical change be reversed?

Back

Yes, many physical changes can be reversed, such as freezing and melting.

Front

Can a chemical change be reversed?

Back

Chemical changes are often not reversible by simple physical means, as new substances are formed.